Border Force officers found the Eritrean men as they searched a lorry which had come from Bulgaria at the port of Dunkerque in Northern France, says a report in the Daily Mail.
A sniffer dog tracked down the men hiding among the boxed coffins, and the stowaways were handed over to French border police.
Paul Morgan, Border Force director for South East and Europe, told the Mail: "This was an unusual type of discovery, but in the past we have found people hiding in an array of freight, ranging from dog biscuits, bathtubs and now coffins.
"The incident shows exactly why we base Border Force staff in France - to stop would-be illegal immigrants before they can reach the UK."
Speaking to AOL Travel, Habib Rahman, Chief Exec of the Joint Council For the Welfare of Immigrants said:
"In the era of Fortress Britain and Fortress Europe, is it really surprising people are forced to go to such lengths to gain access to the UK?
"These are desperate actions by desperate people, they should be dealt with humanely."
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